1 /* 2 * vfsv0 quota IO operations on file 3 */ 4 5 #include <linux/errno.h> 6 #include <linux/fs.h> 7 #include <linux/mount.h> 8 #include <linux/dqblk_v2.h> 9 #include <linux/kernel.h> 10 #include <linux/init.h> 11 #include <linux/module.h> 12 #include <linux/slab.h> 13 #include <linux/quotaops.h> 14 15 #include <asm/byteorder.h> 16 17 #include "quota_tree.h" 18 #include "quotaio_v2.h" 19 20 MODULE_AUTHOR("Jan Kara"); 21 MODULE_DESCRIPTION("Quota format v2 support"); 22 MODULE_LICENSE("GPL"); 23 24 #define __QUOTA_V2_PARANOIA 25 26 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot); 27 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp); 28 static int v2r0_is_id(void *dp, struct dquot *dquot); 29 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot); 30 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp); 31 static int v2r1_is_id(void *dp, struct dquot *dquot); 32 33 static const struct qtree_fmt_operations v2r0_qtree_ops = { 34 .mem2disk_dqblk = v2r0_mem2diskdqb, 35 .disk2mem_dqblk = v2r0_disk2memdqb, 36 .is_id = v2r0_is_id, 37 }; 38 39 static const struct qtree_fmt_operations v2r1_qtree_ops = { 40 .mem2disk_dqblk = v2r1_mem2diskdqb, 41 .disk2mem_dqblk = v2r1_disk2memdqb, 42 .is_id = v2r1_is_id, 43 }; 44 45 #define QUOTABLOCK_BITS 10 46 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS) 47 48 static inline qsize_t v2_stoqb(qsize_t space) 49 { 50 return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS; 51 } 52 53 static inline qsize_t v2_qbtos(qsize_t blocks) 54 { 55 return blocks << QUOTABLOCK_BITS; 56 } 57 58 static int v2_read_header(struct super_block *sb, int type, 59 struct v2_disk_dqheader *dqhead) 60 { 61 ssize_t size; 62 63 size = sb->s_op->quota_read(sb, type, (char *)dqhead, 64 sizeof(struct v2_disk_dqheader), 0); 65 if (size != sizeof(struct v2_disk_dqheader)) { 66 quota_error(sb, "Failed header read: expected=%zd got=%zd", 67 sizeof(struct v2_disk_dqheader), size); 68 return 0; 69 } 70 return 1; 71 } 72 73 /* Check whether given file is really vfsv0 quotafile */ 74 static int v2_check_quota_file(struct super_block *sb, int type) 75 { 76 struct v2_disk_dqheader dqhead; 77 static const uint quota_magics[] = V2_INITQMAGICS; 78 static const uint quota_versions[] = V2_INITQVERSIONS; 79 80 if (!v2_read_header(sb, type, &dqhead)) 81 return 0; 82 if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] || 83 le32_to_cpu(dqhead.dqh_version) > quota_versions[type]) 84 return 0; 85 return 1; 86 } 87 88 /* Read information header from quota file */ 89 static int v2_read_file_info(struct super_block *sb, int type) 90 { 91 struct v2_disk_dqinfo dinfo; 92 struct v2_disk_dqheader dqhead; 93 struct mem_dqinfo *info = sb_dqinfo(sb, type); 94 struct qtree_mem_dqinfo *qinfo; 95 ssize_t size; 96 unsigned int version; 97 98 if (!v2_read_header(sb, type, &dqhead)) 99 return -1; 100 version = le32_to_cpu(dqhead.dqh_version); 101 if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) || 102 (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1)) 103 return -1; 104 105 size = sb->s_op->quota_read(sb, type, (char *)&dinfo, 106 sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF); 107 if (size != sizeof(struct v2_disk_dqinfo)) { 108 quota_error(sb, "Can't read info structure"); 109 return -1; 110 } 111 info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS); 112 if (!info->dqi_priv) { 113 printk(KERN_WARNING 114 "Not enough memory for quota information structure.\n"); 115 return -ENOMEM; 116 } 117 qinfo = info->dqi_priv; 118 if (version == 0) { 119 /* limits are stored as unsigned 32-bit data */ 120 info->dqi_max_spc_limit = 0xffffffffLL << QUOTABLOCK_BITS; 121 info->dqi_max_ino_limit = 0xffffffff; 122 } else { 123 /* 124 * Used space is stored as unsigned 64-bit value in bytes but 125 * quota core supports only signed 64-bit values so use that 126 * as a limit 127 */ 128 info->dqi_max_spc_limit = 0x7fffffffffffffffLL; /* 2^63-1 */ 129 info->dqi_max_ino_limit = 0x7fffffffffffffffLL; 130 } 131 info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace); 132 info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace); 133 /* No flags currently supported */ 134 info->dqi_flags = 0; 135 qinfo->dqi_sb = sb; 136 qinfo->dqi_type = type; 137 qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks); 138 qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk); 139 qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry); 140 qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS; 141 qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS; 142 qinfo->dqi_qtree_depth = qtree_depth(qinfo); 143 if (version == 0) { 144 qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk); 145 qinfo->dqi_ops = &v2r0_qtree_ops; 146 } else { 147 qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk); 148 qinfo->dqi_ops = &v2r1_qtree_ops; 149 } 150 return 0; 151 } 152 153 /* Write information header to quota file */ 154 static int v2_write_file_info(struct super_block *sb, int type) 155 { 156 struct v2_disk_dqinfo dinfo; 157 struct mem_dqinfo *info = sb_dqinfo(sb, type); 158 struct qtree_mem_dqinfo *qinfo = info->dqi_priv; 159 ssize_t size; 160 161 spin_lock(&dq_data_lock); 162 info->dqi_flags &= ~DQF_INFO_DIRTY; 163 dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace); 164 dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace); 165 /* No flags currently supported */ 166 dinfo.dqi_flags = cpu_to_le32(0); 167 spin_unlock(&dq_data_lock); 168 dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks); 169 dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk); 170 dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry); 171 size = sb->s_op->quota_write(sb, type, (char *)&dinfo, 172 sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF); 173 if (size != sizeof(struct v2_disk_dqinfo)) { 174 quota_error(sb, "Can't write info structure"); 175 return -1; 176 } 177 return 0; 178 } 179 180 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp) 181 { 182 struct v2r0_disk_dqblk *d = dp, empty; 183 struct mem_dqblk *m = &dquot->dq_dqb; 184 185 m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit); 186 m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit); 187 m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes); 188 m->dqb_itime = le64_to_cpu(d->dqb_itime); 189 m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit)); 190 m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit)); 191 m->dqb_curspace = le64_to_cpu(d->dqb_curspace); 192 m->dqb_btime = le64_to_cpu(d->dqb_btime); 193 /* We need to escape back all-zero structure */ 194 memset(&empty, 0, sizeof(struct v2r0_disk_dqblk)); 195 empty.dqb_itime = cpu_to_le64(1); 196 if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk))) 197 m->dqb_itime = 0; 198 } 199 200 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot) 201 { 202 struct v2r0_disk_dqblk *d = dp; 203 struct mem_dqblk *m = &dquot->dq_dqb; 204 struct qtree_mem_dqinfo *info = 205 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv; 206 207 d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit); 208 d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit); 209 d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes); 210 d->dqb_itime = cpu_to_le64(m->dqb_itime); 211 d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit)); 212 d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit)); 213 d->dqb_curspace = cpu_to_le64(m->dqb_curspace); 214 d->dqb_btime = cpu_to_le64(m->dqb_btime); 215 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id)); 216 if (qtree_entry_unused(info, dp)) 217 d->dqb_itime = cpu_to_le64(1); 218 } 219 220 static int v2r0_is_id(void *dp, struct dquot *dquot) 221 { 222 struct v2r0_disk_dqblk *d = dp; 223 struct qtree_mem_dqinfo *info = 224 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv; 225 226 if (qtree_entry_unused(info, dp)) 227 return 0; 228 return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type, 229 le32_to_cpu(d->dqb_id)), 230 dquot->dq_id); 231 } 232 233 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp) 234 { 235 struct v2r1_disk_dqblk *d = dp, empty; 236 struct mem_dqblk *m = &dquot->dq_dqb; 237 238 m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit); 239 m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit); 240 m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes); 241 m->dqb_itime = le64_to_cpu(d->dqb_itime); 242 m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit)); 243 m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit)); 244 m->dqb_curspace = le64_to_cpu(d->dqb_curspace); 245 m->dqb_btime = le64_to_cpu(d->dqb_btime); 246 /* We need to escape back all-zero structure */ 247 memset(&empty, 0, sizeof(struct v2r1_disk_dqblk)); 248 empty.dqb_itime = cpu_to_le64(1); 249 if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk))) 250 m->dqb_itime = 0; 251 } 252 253 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot) 254 { 255 struct v2r1_disk_dqblk *d = dp; 256 struct mem_dqblk *m = &dquot->dq_dqb; 257 struct qtree_mem_dqinfo *info = 258 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv; 259 260 d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit); 261 d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit); 262 d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes); 263 d->dqb_itime = cpu_to_le64(m->dqb_itime); 264 d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit)); 265 d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit)); 266 d->dqb_curspace = cpu_to_le64(m->dqb_curspace); 267 d->dqb_btime = cpu_to_le64(m->dqb_btime); 268 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id)); 269 if (qtree_entry_unused(info, dp)) 270 d->dqb_itime = cpu_to_le64(1); 271 } 272 273 static int v2r1_is_id(void *dp, struct dquot *dquot) 274 { 275 struct v2r1_disk_dqblk *d = dp; 276 struct qtree_mem_dqinfo *info = 277 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv; 278 279 if (qtree_entry_unused(info, dp)) 280 return 0; 281 return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type, 282 le32_to_cpu(d->dqb_id)), 283 dquot->dq_id); 284 } 285 286 static int v2_read_dquot(struct dquot *dquot) 287 { 288 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 289 int ret; 290 291 down_read(&dqopt->dqio_sem); 292 ret = qtree_read_dquot( 293 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, 294 dquot); 295 up_read(&dqopt->dqio_sem); 296 return ret; 297 } 298 299 static int v2_write_dquot(struct dquot *dquot) 300 { 301 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 302 int ret; 303 bool alloc = false; 304 305 /* 306 * If space for dquot is already allocated, we don't need any 307 * protection as we'll only overwrite the place of dquot. We are 308 * still protected by concurrent writes of the same dquot by 309 * dquot->dq_lock. 310 */ 311 if (!dquot->dq_off) { 312 alloc = true; 313 down_write(&dqopt->dqio_sem); 314 } 315 ret = qtree_write_dquot( 316 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, 317 dquot); 318 if (alloc) 319 up_write(&dqopt->dqio_sem); 320 return ret; 321 } 322 323 static int v2_release_dquot(struct dquot *dquot) 324 { 325 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 326 int ret; 327 328 down_write(&dqopt->dqio_sem); 329 ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot); 330 up_write(&dqopt->dqio_sem); 331 332 return ret; 333 } 334 335 static int v2_free_file_info(struct super_block *sb, int type) 336 { 337 kfree(sb_dqinfo(sb, type)->dqi_priv); 338 return 0; 339 } 340 341 static int v2_get_next_id(struct super_block *sb, struct kqid *qid) 342 { 343 return qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid); 344 } 345 346 static const struct quota_format_ops v2_format_ops = { 347 .check_quota_file = v2_check_quota_file, 348 .read_file_info = v2_read_file_info, 349 .write_file_info = v2_write_file_info, 350 .free_file_info = v2_free_file_info, 351 .read_dqblk = v2_read_dquot, 352 .commit_dqblk = v2_write_dquot, 353 .release_dqblk = v2_release_dquot, 354 .get_next_id = v2_get_next_id, 355 }; 356 357 static struct quota_format_type v2r0_quota_format = { 358 .qf_fmt_id = QFMT_VFS_V0, 359 .qf_ops = &v2_format_ops, 360 .qf_owner = THIS_MODULE 361 }; 362 363 static struct quota_format_type v2r1_quota_format = { 364 .qf_fmt_id = QFMT_VFS_V1, 365 .qf_ops = &v2_format_ops, 366 .qf_owner = THIS_MODULE 367 }; 368 369 static int __init init_v2_quota_format(void) 370 { 371 int ret; 372 373 ret = register_quota_format(&v2r0_quota_format); 374 if (ret) 375 return ret; 376 return register_quota_format(&v2r1_quota_format); 377 } 378 379 static void __exit exit_v2_quota_format(void) 380 { 381 unregister_quota_format(&v2r0_quota_format); 382 unregister_quota_format(&v2r1_quota_format); 383 } 384 385 module_init(init_v2_quota_format); 386 module_exit(exit_v2_quota_format); 387